Decreasing Time Spent Viewing TV
In 2001 the American Academy of Pediatrics recommended that television viewing among children under two years old be “discouraged altogether”(1) and more than a half dozen other scientific, child and health advocacy organizations and agencies have made similar recommendations.(2)
For children over two, the current recommendation to prevent childhood obesity is to limit recreational screen time to no more than 2 hours per day. The origins of this limit stem from early research documenting a relationship between TV viewing and body fatness.(3,4), These early studies showed that the more hours of TV viewing, the higher the BMI, although not all studies have shown this relationship.(5) One study of more than 4000 8 to 16 year olds (6) used nationally representative NHANES data (considered to be methodologically superior to other studies) and found that obesity prevalence was highest among those children watching 4 or more hours of TV per day and lowest among those watching one hour or less. But evidence was needed that interventions to reduce TV viewing would indeed lead to reduced body fatness or BMI.
This evidence was provided by Tom Robinson(7) who designed a school-based intervention to decrease TV viewing, and documented improvements in body mass index (BMI). Planet Health, another school-based intervention that included reductions in TV viewing as one component,(8) found improvements in BMI in some groups of children, but not all. Subsequent research has broadened the 2 hour per day limit to all forms of recreational screen viewing combined.(9, 10)
In January, 2010, the U.S. Surgeon General, Dr. Regina M. Benjamin, issued a report(11) on the epidemic of overweight and obesity in America. In the discussion of the various causes of obesity, Dr. Benjamin’s report stated that “[t]he more time children spend watching television, the more likely they are to eat while doing so and the more likely they are to eat the high-calorie foods that are heavily advertised on television.”(12) In other words, eating in front of screens – TV screens, computer screens and video screens – promotes mindless munching on high calorie foods and increases exposure to commercial messages for unwholesome snacks and many other products such as movies and DVDs that encourage sedentary forms of entertainment for kids. An earlier report from the Institute of Medicine [IOM](13) details the extent and impact of marketing food to children and its impact on childhood obesity.
According to the IOM,(14) the food and beverage industries spend approximately $10 billion a year on marketing their products through various channels and “the preponderance of the products introduced and marketed for children and youth are high in total calories, sugars, salt, fat, and low in nutrients.”(15) When the report was released in 2006, Senator Harkin of Iowa remarked: “The food industry doesn’t spend $10 billion a year on ads to kids because they like to waste money. Their ads not only work, they work brilliantly.”(16) There is evidence to support Senator Harkin’s statement.(17) Dr. Thomas Frieden, current Director of the Centers for Disease Control and Prevention (CDC), predicted that 20 years from now people will look back and say: “What were they thinking? They’re in the middle of an epidemic and kids are watching 20,000 hours of commercials for junk food.”(18)
Through the use of cartoon characters recruited to pitch products to children and the development of “advergames” and other strategies targeting kids, the Internet, cell phone, DVD and TV marketers are collaborating in their efforts to control “share of mind.” This marketing concept refers to the objective of building “cradle to grave” brand loyalty that threatens to turn our children into passive “super consumers” – indeed supersized consumers.(19) Advertisements for unhealthy foods and sedentary forms of entertainment provide children with “pester power” – and parents get worn down by their children’s constant requests for candy, sweetened cereals, cookies, cupcakes and sugary soda, not to mention the latest movies, computer games and DVDs – all sedentary forms of entertainment.
The percentage increase in the number of new food products targeted to children has skyrocketed(20) and this is because our children and teens have money to spend – as much as $365 billion a year according to one estimate.(21) According to the IOM, television marketing strategies are contributing to the growing problem of childhood obesity: “Statistically, there is strong evidence that exposure to television advertising is associated with adiposity in children ages 2-11 years and teens ages 12-18 years.”(22)
The relationship between screen viewing and physical activity is difficult to study especially since some children may turn off the TV or computer to read a book instead of active play. One study of 2 to 6 year olds used state-of-the-art techniques to quantify fat gain associated with TV viewing.(23) The researchers measured total daily energy expenditure using doubly labeled water and body fat using dual-energy X-ray absorptiometry and physical activity using accelerometry. This exceptionally well designed study showed that each extra hour a child spent watching TV was associated with an increase of about 1 kilogram (2.2 pounds) in body fatness.(23)
Obesity and low aerobic fitness are now considered common among American youth and data are emerging that both are associated with poorer academic performance.(42) One study of nearly 2000 5th, 7th and 9th graders found consistent positive associations between aerobic fitness and math, reading and language test scores and consistently poorer scores in children whose BMI-for-age was elevated.(42) Unpublished data collected by Dr. Steve Gaskill on children in Missoula, MT are consistent with these findings. These data point to the importance of decreasing screen time and encouraging vigorous active play, ideally outdoors, that builds aerobic fitness.
A growing number of studies link screen viewing with decreased play,(24) increased body fatness,(25,26), and a heightened risk of childhood obesity (27,28). Since the publication of the IOM report in 2006, a number of studies have examined how the use of media affect food intake, behavior and body fatness of children (29), (30), (31), (32), (33), (34), (35), (36), (37) and the evidence continues to grow. Some studies suggest that parental limits on TV viewing and other screens is helpful for changing behavior and preventing childhood obesity (38), (39), (40) but that parents need guidance and support to implement changes in screen-viewing policies. (41) According to the 2009 Youth Risk Behavior Survey, one in four Montana high school students report spending three or more hours viewing TV on an average school day. This does not include additional time they may spend playing video or computer games or using computer for non-school purposes.
The website of the Montana Nutrition and Physical Activity [www.MontanaNAPA.org] program is a useful resource for those seeking to implement screen time reduction activities including ways to participate in Screen-Free Week. This site also explains the many other benefits besides obesity prevention that can be derived from reducing screen time, including promoting healthy brain development in young children, supporting healthy eating and sleeping behaviors, and giving families more time to do things together. For more information about screen time reduction see the WE CAN! Website produced in collaboration with the National Institutes of Health. [http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan/reduce-screen-time/tips-to-reduce-screen-time.htm] WE CAN! offers a parent handbook and other useful tools and resources. [See http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan/tools-resources/tools-reduce-screen-time.htm] See also the Center for Screen Time Awareness [www.screentime.org].
* Research for this section was reviewed and compiled by Barbara J. Moore, PhD.
Footnotes:
(1) AAP (American Academy of Pediatrics) Children, adolescents, and television. Pediatrics 2001; 107(2):423-426
(2) Institute of Medicine. Preventing Childhood Obesity: Health in the Balance. National Academies Press, Washington DC 2005, p. 304. This report cites comparable recommendations made by the American Psychological Association, American Medical Association, American Academy of Pediatrics, National Education Association, Department of Health and Human Services, American Academy of Child and Adolescent Psychiatry, National Parent Teachers Association.
(3) Robinson TN et al. Does television viewing increase obesity and reduce physical activity? Cross-sectional and longitudinal analyses among adolescent girls. Pediatrics 1993; 91(2):273-280
(4) Gortmaker SL et al. Television viewing as a cause of increasing obesity among children in the United States, 1986-1990. Arch Pediatr Adolesc Med 1996; 153()4: 356-362
(5) Sallis JF, Prochaska JJ, Taylor WC. A review of correlates of physical activity of children and adolescents. 2000; Med Sci Sports Exerc 32(5):963-975.
(6) Crespo CJ, Smit E, Troiano RP et al. Television watching, energy intake, and obesity in US children: Results from the third National Health and Nutrition Examination Survey, 1988-1994. Arch Pediatr Adolesc Med 155(3): 360-365.
(7) Robinson TN. Reducing children’s television viewing to prevent obesity. A Randomized controlled trial. JAMA 1999; 282(16):1561-1567.
(8) Gortmaker SL, Peterson K, Wiecha J, et al. Reducing obesity via a school-based interdisciplinary intervention among youth: Planet Health. Arch Pediatr Adolesc Med 1999; 153(4):409-418
(9) Institute of Medicine. Progress in Preventing Childhood Obesity: How do we Measure Up? National Academies Press, Washington DC 2007: p. 327.
(10) Institute of Medicine. Preventing Childhood Obesity: Health in the Balance. National Academies Press, Washington DC 2005; p. 308.
(11) U.S. Department of Health and Human Services. The Surgeon General’s Vision for a Healthy and Fit Nation. Rockville, MD: Office of the Surgeon General, January 2010.
(12) U.S. Department of Health and Human Services. The Surgeon General’s Vision for a Healthy and Fit Nation. Rockville, MD: Office of the Surgeon General, January 2010, p. 4.
(13) Institute of Medicine [IOM]. Food Marketing to Children and Youth: Threat or Opportunity? National Academies Press 2006, 500 Fifth Street NW, Washington DC 20001 [The Institute of Medicine was established in 1970 by the National Academy of Sciences. The IOM convenes appropriately credentialed professionals to examine “policy matters pertaining to the health of the public.” ]
(14) See the IOM report (reference 3), page 4.
(15) See IOM report (reference 3), page 4
(16) Quoted by M. Burros, “Federal Advisory Group Calls for Change in Food Marketing to Children” NYTimes.com, December 7, 2005
(17) Borzekowski DL, Robinson TN. The 30-second effect: an experiment revealing the impact of television commercials on food preferences of preschoolers. J Am Diet Assoc 2001; 101(1):42-46
(18) Quoted by N.R.Kleinfield, “Diabetes and Its Awful Toll Quietly Emerge as a Crisis” NYTimes.com, January 9, 2006
(19) Samuels et al. “Food and Beverage Industry Marketing Practices Aimed at Children: Developing Strategies for Preventing Obesity and Diabetes”, November 2003, A Report on the Proceedings from a meeting sponsored by the California Endowment, held in San Francisco June, 2003.
(20) See Williams J. “Product Proliferation Analysis for New Food and Beverage Products Targeted to Children 1994-2004. University of Texas at Austin Working Paper.
(21) See Samuels et al. (reference 9).
(22) IOM report (reference 3), page 9.
(23) Jackson DM, Djafarian K, Stewart J, Speakman JR. Increased television viewing is associated with elevated body fatness but not with lower total energy expenditure in children. Am J Cin Nutr. 2009; 89(4):1031-1036
(24) Schmidt ME, Pempek TA, Kirkorian HL, et al. The effects of background television on the toy play behavior of very young children. Child Development 2009; 79(4): 1137-1151
(25) Robinson TN. Television viewing and childhood obesity. Pediatr Clin North Am 48(4)” 1017-1025
(26) Jackson DM, Djafarian K, Stewart J, Speakman JR. Increased television viewing is associated with elevated body fatness but not with lower total energy expenditure in children. Am J Clin Nutr 2009; 89:1031-1036.
(27) Institute of Medicine. Preventing Childhood Obesity: Health in the Balance. National Academies Press, Washington DC 2005; pp. 301-305.
(28) Mendoza JA, Zimmerman FJ, Christakis DA. Television viewing, computer use, obesity, and adiposity in US preschool children. International Journal of Behavioral Nutrition and Physical Activity 2007, 4:44doi:10.1186/1479-5868-4-44 [The electronic version of this article is the complete one and can be found online at: http://www.ijbnpa.org/content/4/1/44; accessed March 13, 2010]
(29) Chamberlain LJ, Wang Y, Robinson TN. Does children’s screen time predict requests for advertised products ? Cross-sectional and prospective analyses. Arch Pediatr Adolesc Med. 2006; 160(4):363-368.
(30) Bellisimo N, Pencharz PB, Thomas SG, Anderson GH. Effect of television viewing at mealtime on food intake after a glucose preload in boys. Pediatr Res. 2007; 61(6): 745-749.
(31) Blass EM, Anderson DR, Kirkorian HL, et al. On the road to obesity: Television viewing increases intake of high-density foods. Physiol Behav. 2006; 88:597-604
(32) Francis LA, Birch LL. Does eating during television viewing affect preschool children’s intake? J Am Diet Assoc. 2006; 106(4): 598-600
(33) Fitzpatrick E, Edmunds LS, Dennison BA. Positive effects of family dinner are undone by television viewing. J Am Diet Assoc. 2007; 107:666-671
(34) Kirkorian HL, Pempek TA, Murphy LA, et al. The impact of background television on parent-child interaction. Child Development 2009; 80(5): 1350-1359
(35) Chou S-Y, Rashad I, Grossman M. Fast-food restaurant advertising on television and its influence on childhood obesity. J Law Economics 2008; 51:599-618
(36) Martin CK, Coulon SM, Markward N, et al. Association between energy intake and viewing television, distractibility, and memory for advertisements. Am J Clin Nutr 2009; 89:37-44
(37) Anschutz DJ, Engels RCME, VanStrien T. Side effects of television food commercials on concurrent nonadvertised sweet snack food intakes in young children. Am J Clin Nutr 2009; 89:1328-1333
(38) Anderson SE, Whitaker RC. Household routines and obesity in US preschool-aged children. Pediatrics 2010; 125:420-428
(39) Coon KA, Goldberg J, Rogers BL, Tucker KL. Relationships between use of television during meals and children’s food consumption patterns. Pediatrics 2001; 107(1):E7
(40) Robinson TN, Saphir MN, Kraemer HC et al. Effects of reducing television viewing on children’s request for toys : a randomized controlled trial. J Dev Behav Pediatr 2001; 22(3): 179-184
(41) Jordan AB, Hersey JC, McDivitt JA, Heitzler CD. Reducing children’s television-viewing time: A qualitative study of parents and their children. Pediatrics 2006; 118:e1303-e1310
(42) Roberts CK, Freed B, McCarthy WJ. Low aerobic fitness and obesity are associated with lower standardized test scores in children. J Pediatrics 2010; Jan 25 online.